# Iterator

class Squares:

    def __init__(self, start, stop):
        self.value = start - 1
        self.stop = stop

    def __iter__(self):
        return self

    def next(self):
        if self.value == self.stop:
            raise StopIteration
        self.value += 1
        return self.value ** 2

for i in Squares(1,5):
     print i,
     
X = Squares(1,5)

print [n for n in X]
